Personality Differences in Body-temperature Rhythm, and their Relation to its Adjustment to Night Work

Abstract

A re-analysis of Blake's (1967) data indicated that the difference he observed in the temperature rhythm of introverts and extraverts was considerably more marked in ‘neurotic’ than in ‘stable’ subjects. That this difference may be related to the ease with which the rhythm adjusts to a phase change is demonstrated (a) by an examination of the persistence of the pre-flight rhythm immediately after an 8 h eastward time-zone transition (phase advance), and (b) by an assessment of the trends in temperature during a 12 h night shift (phase delay). In both cases the temperature of ‘neurotic’ extraverts exhibited the greatest degree of adjustment. It is further shown that the temperature of extraverts is more variable from day to day than that of introverts. It is suggested that, taken together, these findings may reflect the existence of an underlying periodicity greater than 24h in at least ‘neurolic’ extraverts, and that (to some extent) this group may correspond with the ‘evening’ type identified in other research.